from utils import ListNode, construct_linklist, pretty_linklist
def merge_two_lists(l1, l2):
l = head = ListNode(0)
while l1 and l2:
if l1.val <= l2.val:
l.next, l1 = l1, l1.next
else:
l.next, l2 = l2, l2.next
l = l.next
l.next = l1 or l2
return head.next
if __name__ == '__main__':
h1 = construct_linklist([1, 2, 4])
h2 = construct_linklist([1, 3, 4])
print(pretty_linklist(merge_two_lists(h1, h2)))
tmp = node.next
if node.val > first_pivot.val:
node.next = last_pivot.next
last_pivot.next = node
elif node.val < first_pivot.val:
node.next = start.next
start.next = node
else:
node.next = last_pivot.next
last_pivot.next = node
last_pivot = last_pivot.next
node = tmp
return [first_pivot, last_pivot]
def qsort(start, end):
if start.next != end:
first_pivot, last_pivot = partition(start, end)
qsort(start, first_pivot)
qsort(last_pivot, end)
head_pre = ListNode(0)
head_pre.next = head
qsort(head_pre, None)
return head_pre.next
if __name__ == '__main__':
l1 = construct_linklist([4, 2, 1, 3])
l1 = sort_list(l1)
print(pretty_linklist(l1))
from utils import construct_linklist, pretty_linklist, ListNode
def reverse_list(head: ListNode) -> ListNode:
prev = None
while head:
head.next, prev, head = prev, head, head.next
return prev
if __name__ == '__main__':
h1 = construct_linklist([1, 2, 3, 4, 5])
print(pretty_linklist(h1))
h2 = reverse_list(h1)
print(pretty_linklist(h2))
from utils import construct_linklist, pretty_linklist, ListNode
def delete_node(node: 'ListNode'):
node.val = node.next.val
node.next = node.next.next
if __name__ == '__main__':
head = construct_linklist([1, 2, 3])
print(pretty_linklist(head))
to_del = head.next.next
delete_node(to_del)
print(pretty_linklist(head))
from utils import construct_linklist, ListNode
def print_list_reverse(head: ListNode) -> list:
stack, h = [], head
while h:
stack.append(h.val)
h = h.next
return stack[::-1]
l1 = (1, 2, 3, 4, 5)
print(l1)
l1 = construct_linklist(l1)
lst1 = print_list_reverse(l1)
print(lst1)
l2 = [3, 4, 8, 2, 7]
print(l2)
l2 = construct_linklist(l2)
lst2 = print_list_reverse(l2)
print(lst2)
from utils import construct_linklist, ListNode
def print_list_reverse(head: ListNode) -> list:
stack, h = [], head
while h:
stack.append(h.val)
h = h.next
return stack[::-1]
if __name__ == '__main__':
l1 = (1, 2, 3, 4, 5)
l1 = construct_linklist(l1)
print(print_list_reverse(l1))
import sys
sys.path.append("..")
from utils import construct_linklist
def get_intersection(h1, h2):
p1, p2 = h1, h2
while p1 is not p2:
# NOTICE THE BUG
# p1 = p1.next if p1.next else h2
# p2 = p2.next if p2.next else h1
p1 = p1.next if p1 else h2
p2 = p2.next if p2 else h1
return p1
if __name__ == '__main__':
h1 = construct_linklist([4, 2, 1, 5, 5, 7])
h2 = construct_linklist([8, 3])
h2.next.next = h1.next.next
intersection = h1.next.next
print(intersection is get_intersection(h1, h2))
h1 = construct_linklist([4, 2, 1, 5, 5, 7])
h2 = construct_linklist([8, 3])
print(get_intersection(h1, h2))